Primary Graft Dysfunction (PGD) is severe acute lung injury after lung transplantation. PGD has a major impact on outcomes following lung transplantation, markedly increasing morbidity, mortality, and cost. Thus, reduction in the incidence of PGD would dramatically improve clinical and economic outcomes following lung transplantation. Despite the clear importance of PGD to lung transplantation, fundamental questions about mechanisms that increase PGD risk remain unanswered. Type V collagen [col(V)] is a native lung collagen that may become exposed and cause autoimmunity in the setting of lung inflammation. Recent work by our group suggests that both humoral and cellular immunity to col(V) are involved in PGD pathogenesis. Furthermore, our prior studies suggest that autoimmunity to col(V) is present in recipients prior to the transplant procedure and may thus be used to predict PGD. However, the pre-transplant lung diseases associated anti-col(V) immunity have not been defined, and the utility of this immune response as a predictor of PGD is unknown. Furthermore, the T cell subset involved in anti-col(V)-induced PGD is unknown, and mechanisms of anti-col(V) antibody mediated injury have not been reported. Utilizing a large prospective multicenter clinical study, and our rat lung transplant model that reproduces the clinical condition, we hypothesize that autoimmunity to col(V) influences the risk of PGD following lung transplantation in recipients, and can be utilized to predict PGD. This translational application combines the strengths of the two principal investigators whom were the first to define clinical PGD, and anti- col(V) immunity in the pathogenesis PGD. The application will leverage data collected as part of the Lung Transplant Outcomes Group, which is an ongoing 10 center cohort study of PGD pathogenesis, with Dr. Christie as PI. Laboratory aims will be expand prior discoveries by Dr. Wilkes at IU. The goals of our Aims are to provide insight into the mechanisms of PGD by anti-col(V) autoimmunity in human and laboratory models, to test the utility of anti-col(V) antibodies in prediction of clinical PGD, and to set the stage for clinical trials of tolerance strategies to col(V) in lung transplantation. To achieve these aims, both laboratory and clinical methods will be employed to provide a comprehensive, integrated body of knowledge on the role of col(V) autoimmunity in PGD pathogenesis. Clinical and biological aims will be fully integrated to apply mechanistic insight from laboratory to human populations, and to test the mechanistic underpinnings of clinical observations. The output of this application will provide needed data for potential clinical trials.